Book Excerpt: GWT in Action, Working With Widgets

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News: Book Excerpt: GWT in Action, Working With Widgets

  1. Widgets are the visible components of a GWT application. For example, buttons, labels, images, or the menu system are all widgets. They are one of three fundamental building blocks of GWT applications, along with panels and events. When a user fires up a GWT application, they are looking at a set of widgets that have been positioned by panels and which react to events. Luckily, GWT provides many different widgets for free, and these include the usual suspects of buttons, textboxes, and menus. In this excerpt from GWT in Action, we take a closer look at the standard GWT widgets. You'll see that in the GWT world, widgets are modeled as DOM elements but also have a Java object equivalent. It is this dual existence that provides the power of GWT - the ability to write and maintain applications in Java, with all the associated tool support, but to execute those applications in a web browser. Early chapters of GWT in Action are now available online via Manning’s early access program. Click here to learn more and start reading it today. Read GWT in Action: Working With Widgets

    Threaded Messages (20)

  2. I will prefere DOJO Sudhir Nimavat
  3. Thats kind of an apples and oranges comparison. Personally I like gwt a lot. It's like a breath of fresh air from all the front controller frameworks and makes a lot more sense than jsf. Now if only non-programmers where able to customize the interface by other means than css...
  4. GWT?[ Go to top ]

    Apparently the Google Web Toolkit. I wouldn't assume this to be a wide spread name as SOAP, HTML or J2EE. The editorial quality drops lower and lower here. Some sarcasm: I am totally amazed that people need explanation that a gui application is comprised of or that a gui toolkit features "panels, widgets and events" (and I would surely hope that a panel *is* a widget!). Really? How utterly surprising that a gui is comprised of the same basic building blocks for the last 15 years or so!
  5. Re: GWT?[ Go to top ]

    Really? How utterly surprising that a gui is comprised of the same basic building blocks for the last 15 years or so!
    You obviously didn't grew up on Struts ;)
  6. Since the cover of the book is: GWT in Action Easy Ajax with the Google Web Toolkit By Robert Hanson and Adam Tacy ISBN: 1-933988-23-1 I don't think they are assuming too much about everyone recognizing what GWT means.
  7. Google Web Toolkit[ Go to top ]

    With GWT, we can build our applications using a real object-oriented language and take advantage of Java tools like Eclipse that are already available. Developer Zone
  8. Interesting excerpt for an interesting technology. But the more I think about it, the more I like the concepts of Adobe Flex and Microsoft XAML WPF/E (Windows Presentation Framework / Everywhere). HTML is not a good way to build rich and user friendly GUI (Graphic User Interface), even with Javascript and AJAX. Java is also not an easy way to build GUI - too painful to layout the component, too developper-centric; GWT, which is a mix, is verbose and heavyweight (it's still an elegant solution to develop with, but it must cope with HTML limitations). The best way is to build GUI with good graphical tools, with a technology specifically created for GUI. For now, I only see Adobe Flash and its Microsoft's clone (XUL may become a solution if it gets good graphical tools and good ID integration). (I hope I didn't use too many acronyms...) Cyril
  9. HTML is not a good way to build rich and user friendly GUI (Graphic User Interface), even with Javascript and AJAX.
    Exuse moi? google.maps, gmail, google spreadsheets & docs , google calendar etc etc are amongst the applications that are the most userfriendly around IMHO and it is all HTML. It is not about HTML, javascript or whatever, it is about how well one encapsulates it.
  10. google.maps, gmail, google spreadsheets & docs , google calendar etc etc are amongst the applications that are the most userfriendly around IMHO and it is all HTML.
    I do not agree on that. If you look at a flash based email client (like goowy, if this project is still alive), it is far better than google version of a light mail client (only for the user experience, I don't speak about the functionnalities). The most impressive component of google applications use Flash, not HTML (charting component of google finance). And some HTML components of picasa web album (like the slideshow, which is really great) would be a lot better and easier to do in flash than in GWT. If you need some multimedia functionnalities (sound, video), Flash is the best answer (like in google video). Some GUI will never be possible with HTML and Javascript (or with very bad performances and a lot of complexity), like Gliffy (http://www.gliffy.com/). And please, keep in mind that Google is the most advanced company for AJAX applications, with some of the best developpers around. They pushed HTML and AJAX to their last limits but a GUI constructed with HTML and Javascript will never be as rich as Flash, and programming a GUI in Java (like with GWT) will never be as easy as designing an application with a good GUI Builder. (I don't work for Macromedia/Adobe, but since the relative failure of Java applets - Swing is too verbose and too heavy to develop with - and until the microsoft answer to Flash, they have the best GUI technology, IMHO). Cyril
  11. partly flash is OK as add on but all flash is a nogo IMHO, too slow. Laszlo didnt made a dhtml renderer for nothing. Matisse seems to be a good GUI designer so that could work for GWT also. Gui code is always better than Gui markup IMHO. Markup is terrible in regard to refactoring and OO semantics, I wish people would see that more but most dont.
  12. Flash & Flex are nice, but they are no panacea. Flash breaks the back button, history, bookmarks, and has no permanent links. It also messes with right click, and makes it difficult to copy & paste text that isn't in a text box. All of which make it a poor choice for a public site (not so bad for an intra/extranet though). Flex is also a very strongly commercial offering. I wouldn't mind paying the $800 for the drag & drop gui if that were it. No, then I have to make the choice between XML web services (kill me now!) or $20k/cpu (1 CPU isn't enough, nor is 100 concurrent users) -- which is too expensive. Besides all that, I really dislike the markup stuff they are using to define the GUI. I'm just not really a fan of markup for a (very interactive) gui, though a lot of people disagree with me on that obviously. GWT has its rough edges -- like the lack of a huge component library. But in contrast to flex, it doesn't mess around with browser conventions, can be deployed on as many CPUs as I need, and all the interactivity I'll ever need for free. Pretty darn good.
  13. Besides all that, I really dislike the markup stuff they are using to define the GUI. I'm just not really a fan of markup for a (very interactive) gui, though a lot of people disagree with me on that obviously.
    At least I am with you.
  14. all flash is a nogo IMHO, too slow.
    Rightful argument.
    Gui code is always better than Gui markup IMHO. Markup is terrible in regard to refactoring and OO semantics
    I agree with that. The point is that neither code nor markup is good for designing GUI. The designer must not have to deal with text (code or markup), only with a good tool.
    Flash breaks the back button, history, bookmarks, and has no permanent links. It also messes with right click, and makes it difficult to copy & paste text that isn't in a text box. All of which make it a poor choice for a public site (not so bad for an intra/extranet though)
    Good points.
    Flex (...) too expensive.
    Ok. We need a good Open Source framework which could replace (and improve) Flex Data Service (the expensive part of the technology).
    GWT (...) Pretty darn good.
    Yes, true. The limitations come from HTML/Javascript, and the programmatic way to build component (markup or code). To create a graphic interface, we need graphic tools.

    Think about image editing. A programming language to manipulate images (we can do that in Java, per instance) is a lot less easy to use than a program like Paint or Photoshop.
    The idea is to have some kind of photoshop to design GUI, and that the file format to store this GUI is as easy to manipulate as jpeg (there are tons of software to manipulate easily jpeg). Cyril
  15. I do not agree on that. If you look at a flash based email client (like goowy, if this project is still alive), it is far better than google version of a light mail client
    And a dekstop client like Thunderbird beats both, by far. And you can build a network-deliverable and updatable desktop client with any RCP, Eclipse or Netbeans', no HTML, no Javascript, etc. ----- Gustavo.
  16. It looks very interesting. I've never expirmented myself with this technology, but its main drawback seems to be a lack of components. Compare the minimal set of components in GWT to those in zk or IceFaces or Tibco... I would say that would have to be their top priority. Mike
  17. Using GWT with other frameworks?[ Go to top ]

    Sorry for that newbie question. Could we use GWT with other frameworks (e.g. jsf & facelets, Struts2 ...) as Ajax4jsf?
  18. Can anyone help me understand 1. Can I certify a widget using my regular SSL certificates Not for encrypting the data back n forth, but just to inform customer that this widget is a authentic widget. 2. Is there any chance widgets can be smart enough in future to do decryption of data too ?
  19. Can anyone help me understand
    1. Can I certify a widget using my regular SSL certificates
    Not for encrypting the data back n forth, but just to inform customer that this widget is a authentic widget.

    2. Is there any chance widgets can be smart enough in future to do decryption of data too ?
    1. What's the point? The widgets are Javascript to the client's eyes, there is no reason to sign them. I don't think I have ever come across signed javascript code in my life. Applets, yeah, but not javascript. If you ever *do* want to encrypt the communication, a normal SSL certificate will do just fine. GWT's rpc works over SSL without any special programming. 2. Javascript (and thus, gwt) can already do decryption. I have seen a few academic examples around. It is rather slow, however, so not usually a good idea. If you ever did do this in GWT, it would probably be custom javascript rather than a widget really.
  20. GWT vs Flex[ Go to top ]

    I believe that both tools will be in the top list of the next generation web development tools. I found an interesting GUI designer for GWT, it is called GWT Designer (http://www.instantiations.com/gwtdesigner/index.html). It is made by the same guys who did the SWT Designer that is a pretty mature an efficient tool. For Flex/Flash, I think it is a wonderful technology for any rich applications development. The only problems I see is the price and the fact that it is not based on a standardized technology like HTML. Should we follow the guys who makes great things by not encumber themself with standards(HTML) ?
  21. Re: GWT vs Flex[ Go to top ]

    Try this: OpenLaszlo (http://www.openlaszlo.org/)